The invention relates to methods and devices for processing wafer-shaped articles, such as semiconductor wafers.
Semiconductor wafers are subjected to various surface treatment processes such as etching, cleaning, polishing and material deposition. To accommodate such processes, a single wafer may be supported in relation to one or more treatment fluid nozzles by a chuck associated with a rotatable carrier, as is described for example in U.S. Pat. Nos. 4,903,717 and 5,513,668. Such chucks are typically provided with a surrounding collector to handle the liquids discharged during processing, as well as to vent the gases used during processing.
In order that a wafer may undergo multiple process steps while positioned on a same chuck, collectors have been designed that permit the wafer to be positioned at each of plural process levels, as described for example in U.S. Pat. No. 4,903,717. Collectors have also been designed in which a series of vertically movable partitions are arranged concentrically around the chuck, as described for example in U.S. Pat. No. 6,810,888 and Japanese Patent Publication No. 2004-265910, so as to define separate liquid collection regions depending on the position of the partitions.
In the latter category of processing apparatus, however, there remains a need for equipment that can adequately handle both the liquid discharge and the gaseous exhaust separately for each process stage, in a device that is practical for use in a commercial production environment.